Calculating machine



1 5, 1932- A R. HOFGAARD 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 sheets-sheet 1 INVENTOR folfzbfyuolzi 14; A'ITORNEYS Sept. 6, 1932. 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 Shets-Sheet 2 IIII/II/II/M/J/M 1 INVENTOR :L ATTORNEYS Sept 6 1932 R. HOFGAARD CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet 3 7196 I6 86 INVENTOR J iiol/Haf'gaara! Y M M 12,4 1M

4:1 ATTORNEYS Sept. 6, 1932, R. HOFGAARD CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet 4 INVENTOR 1 60/1 [lo/guard 3414 441M Sept. 6, 1932. HQFGAARD 1,876,296

CALCULATING MACHINE -44 ATTORN EYS Sept. 6, 1932. HFGAARD 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet 7 INVENTOR ATTORNEYS Sept. 6, 1932.

R. HOFGAARD CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet 8 INVENTOR ATTORNEYS Sept. 6, 1932. v HFGMRD 1,876,296

CALCULATING MACHINE v Filed March 12, 1929 19 Sheets-Sheet 9 1 INVENTOR 9 J27 ital/Hoiaard BYM I'M 25- J32 9 J J L ATTORNEYS Sept. 6, 1932. 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet ll 1 ATTORNEYS pt. 6, 1932. FGAARD CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet l2 ATTORN EYS Sept. 6, 1932. HFGAARD 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet l5 INVENTOR fo/f'lyoif aald 74.1 4% flu/Q 1 ATTORNEY5 H P 1932- Q R. HOFGAARD 1,876,296

' CALCULATING MACHINE I Filed March 12, 1929 19 Sheets-Sheet 14 q mym 45*54 INVENTOR Ro/f'flofgaara' M YM l AITORNEYS Sept. 6, 1932. oFGAARD I 1,876,296

CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet l5 S03 ATTORNEYS Sept. 6, 1932. HOFGAARD 1,876,296

CALCULATING MACHINE Filed March 12, 1929 9 Sheets-Sheet 16 INVENTOR Ko/f'ffoiaard PM #04 A; ATTORNEYS CALCULATING MACHINE Filed March 12, 1929 l9 Sheets-Sheet l7 INVENTOR I Ro/fllofgM/d ATTORNEYS CALCULATING MACHINE Filed March 12, 1929 19 Sheets-Sheet l8 101 /00 INVENTOR Ro/fflolaard BY W W 701-04 ATTORNEYS Patented Sept. 6, 1932 UNITED STATES PATENT oar-ice ROLF EOFGAABD, OF STABEKK, NEAR OSLO, NORWAY, ABSIGNOB TO nomahnn-nm. INGTON CORPORATION, OF NEW YORK, N. Y A CORPORATION OF DELAWARE cnlcumrme mom Application filed Kai-ch18, 1m, Serial in. 848,892, and 1.. Great Britain 1mm 1:, ma.

of my copending application Ser. No. 292,388,

' filed July 13, 1928.

The present invention has for its object an electric calculating machine which is based on the general broad principle .of operation described and claimed in my copending U. S.

patent applications Serial Number 688,564, filed January 25, 1924 and Ser. No. 221,330 filed September 22, 1927; and this application is, as to certain features, a continuation in part of the said applications.

According to the principle of operation de scribed and claimed in the afore-mentioned patent applications, the electric culculating machine comprises two sets of 10 digit lines, said digit lines being adapted to be interconnected in 10 different group combinations through suitable contact units by the closing of contacts corresponding to the various numbers entering into the calculation, and each group combination again comprises 10 possible single combinations as between individual digit lines. Therefore, there are, as between individual digit lines .100 possible combinations between the two sets of each ten digit lines.

In the present embodiment I elect to employ as in said applications sets of relays, the relaysof a given setcorresponding'in number to the digits of the numerical monetary or other system for which the machine is adapted to be used, i. e. in the ten-digit system of numbers, I employ ten relays in each set, each relay corresponding ,respectively to the digit values 1-0 inclusive; and respective relays each having contact means representing digit values 1-0 inclusive.

The machine also comprises registering elements, each of which is adapted to be operated by a currentpassing throu h a linein one of the afore-mentioned sets 0 digit lines. The said registering elements in turn control contact members for closing said lines in the other set of digit lines.

' In a calculating machine of this kind, the effectof depressing a certain key on the key board will, depend on the key of the same denominational value previously depressed, the result registered being equal to any func- .cally operated tion of the digits corresponding to the said keys for which the particular machine is constructed.

Thus, in an adding machine for sin 1e numbers, if key No. 3 has been depressed, tie depression of key No. 4, owing to the combination in which the two sets of 10 digit lines have been connected by the key N o. 3, through one of the relays in the interconnecting sets of relays, will actuate the registering element for N0. 7, and so on. i

In the calculating machine, according to this princlple which wasdescribed in the afore-mentioned patent application Serial Number 688,564, the means for successively reglstering the effects of depressions of the keys consist in a ribbon or strip which is caused to be perforated by means of electrierforating members, said perforations actin to establish the contacts for closing the diglt line circuit upon the depression of the next key.

In my copending U. S. application Ser. No. 221,330, filed September 22, 1927, I have disclosed an improved manner of recording and registering, such for example as by means of relays. The present invention embodies this improvement and in this respect is in part a continuation of said last-mentioned application.

One object of the present invention-is to provide an electric calculating machine of the t pe specified by means of which it is possible to perform all the four principal kinds of calculation, that is, addition, subtraction, multiplication and division, by means of one sin le set of digit keys, corresponding in numher to the digit system employed, i. e. in the present embodiment a series of 10 keys, with an appro riate number of control keys for setting t e machine for the calculation to be performed.

Another object of the present invention is to provide an electric calculating machine of the type specified, comprising the least possible amount of mechanical elements commensurate with the preferred manner of performance. The machine, according to the present invention, comprising principally a combination of multiple contact relays 

